Deck 5

Question 1

2 laws of thermodynamics

Answer 1

1) energy is not created or destroyed, only transferred and transformed
2) every energy transfer or transformation increase the entropy of the surrounding over time

Question 2

Entropy

Answer 2

Tendency for energy to become dispersed or spread out

• randomness, increased chaos

Question 3

Heat

Answer 3

• Loss of energy from chemical reactions
• most disorganized form of energy
• increase in entropy

Question 4

Spontaneous

Answer 4

Release of energy= increase in entropy
- exergonic
- requires enzymes

Question 5

Non spontaneous

Answer 5

Energy needs to be added
- endergonic
- creates localized area of lower entropy

Question 6

Exergonic

Answer 6

• Negative delta G
• release of free energy

Question 7

Endergonic

Answer 7

Absorbs free energy from surrounding
- positive delta G

Question 8

Metabolism

Answer 8

• all of an organisms chemical reaction
• organized into pathways

Question 9

Metabolic Pathway

Answer 9

Chemical reactions from starting material to an ending material
- each step catalyzed by a different enzyme

Question 10

Catabolic pathway

Answer 10

• Break down complex molecules into simpler molecules
• exergonic
• release free energy
• requires enzymes

Question 11

Anabolic Pathway

Answer 11

Chemical reactions that build complex molecules
- requires energy
- endergonic
- requires enzymes

Question 12

Energy coupling

Answer 12

Energy released from 1 reaction is used to power another reaction

• catabolic reaction energy released is used to power anabolic reactions

Question 13

ATP

Answer 13

Adenosine Tri Phosphate
-3 phosphate groups
- ribose sugar
- adenine nitrogen base

Question 14

Use of ATP in cells

Answer 14

1) Movement- transport vesicles through cells
- flagella and cilia

2) Transport
- against concentration gradient

3) chemical
- driving endergonic chemical reactions

Question 15

How does ATP release energy

Answer 15

Terminal end phosphate is removed ATP - ADP + Pi

• hydrolysis
• exergonic

Question 16

Why is ATP hydrolysis exergonic

Answer 16

Repulsive forces between negatively charged phosphate groups make ATP less stable than ADP

Question 17

How does ATP harness the released energy

Answer 17

G = -7.3 kcal/mol- energy available

Harnesses the energy by phosphorylation

Question 18

Phosphorylation

Answer 18

Phosphate from ATP hydrolysis is added to another molecule( destabilization of that molecule)

Question 19

What does Phosphorylation do generally as well as its effect on different proteins

Answer 19

1) makes molecules more reactive
- causes endergonic reactions to occur
2) transport proteins- causes protein to change shape
3) bind and hydrolyze ATP can cause protein to change shape ( motor proteins)

Question 20

ATP cycle

Answer 20

Constantly makes ATP by re-phosphorylation of ADP

Question 21

Redox

Answer 21

Transfer of electrons between reactants
- needs oxidation and reduction

Question 22

Energy released in redox

Answer 22

Release of energy going from less electronegativity to higher

High energy= non polar
Low energy = polar

Question 23

Electron Shuttle Moleculesb

Answer 23

Temporary storage site for high energy electrons

Question 24

Dehydrogenase

Answer 24

Enzyme that removes 2H atoms from high energy substrates to shuttle molecules

Question 25

Electron transport chains

Answer 25

- electron carrying membrane proteins that transfer electrons and release energy - glucose

Question 26

Enzyme

Answer 26

Catalytic protein that speeds up a reaction without being consumed - increase reaction rate - doesn’t change reaction, entropy or enthalpy - doesn’t provide energy - increase rate of reaction by lowering activation energy

Question 27

Active site

Answer 27

Where substrate binds to enzyme - specific shape for substrate

Question 28

Process of enzymes and substrates

Answer 28

1) substrate enters active site - enzyme changes shape to interact with substrate( induced fit) 2) substrate held in place in active site - h bonds, hydrophobic interactions, charge interactions form between active site and substrate 3) Activation energy is lowered by active site 4) substrate is converted to products that have different shape than substrate

Question 29

How does the enzyme lower the activation energy

Answer 29

1) lines up substrate correctly for new bonds 2) stresses bonds in substrates 3) creates a charge environment that favours the reaction

Question 31

Factors effecting Enzyme activity

Answer 31

1) concentration of substrate - more substrate=faster reaction time - rate increases till all active sites are full( saturated) 2) concentration of enzyme - more = faster reaction - must have enough substrate 3) Temp - more temp = faster reaction - too much heat= denature of enzymes 4) pH - changes in pH= changes in protein shape and ability for substrate to bind in active site 5) cofactors and co enzymes

Question 32

Cofactors and Coenzymes

Answer 32

Cofactors- metal ions/ inorganic minerals Coenzymes- organic molecules Non protein helpers required for function

Question 33

Enzyme inhibitors

Answer 33

Chemicals that decrease activity of enzyme Eg) chemicals, drugs, poisons

Question 34

Irreversible inhibitors

Answer 34

- bind to enzyme using covalent bonds - permanent inactivation

Question 35

Reversible inhibitors

Answer 35

- bind using hydrogen bonds - temporary inactivation

Question 36

Competitive inhibitors

Answer 36

- mimics normal enzyme - competes with substrate for binding - blocks active site and prevents formation of complex - overcome with more substrate

Question 37

Non- competitive inhibitors

Answer 37

- bind to region of enzyme other than active site - changes shape of enzyme - not overcome with more substrate